Interference of Light: Young's Experiment
Approximately 200 years ago, scientists (then called natural
philosophers) argued about the fundamental nature of light.
In his book Optiks,
Isaac Newton assumed that light consisted of a collection of
minute particles. With this model, he explained most of the known
optical experiments. Others thought that light must take the
form of a wave. In 1801, Thomas Young completed an experiment
that seemed to end this controversy.